All Graupner HoTT receivers provide telemetry of signal quality, receiver voltage, temperatures and on some also altitude.
You can setup telemetry alarm values directly on the receivers that when a preset value has been reached, you will be notified of such condition.
Settings can be made by using the settings and data view menu on your radio.
Navigate to the last menu page of the receiver to make changes to the Min/Max temperatures and minimum voltage.
On the first menu page of the receiver, you can make changes Max temperatures and minimum voltage. Depending on your receiver type you can also set the maximal altitude alarm.
NOTE: On newer Graupner radios like the mz-16 and mz-32 you can make all these setting directly on the radio.